&CELL: PERIODICITY


direction

  The direction in which the cell is infinitely repeated. Repetition
  in r is not permitted because of the method used to calculate the
  potentials in cylindrical geometry.

  Cylindrical geometries are handled via a conformal mapping onto a
  Cartesian coordinate system. An r-periodicity would becomes an
  x-periodicity with non-constant intervals, which is technically
  difficult to deal with. Contact the author if there is a need for
  such a periodicity.

length

  The length of one full period in cm for x and y periodicities and
  in degrees for periodicity in phi.

Keyword index. Formatted on 10/11/98.